One-pot ultrasonic assisted sol-gel synthesis of spindle-like Nd and V codoped ZnO for efficient photocatalytic degradation of organic pollutants

Synthesis of visible light active photocatalyst with desirable control on recombination of charge carriers is prerequisite for photocatalysis. The simultaneous doping of two metals into oxide semiconductor materials is considered to be an efficient strategy to alleviate the charge carrier recombination and to improve the photocatalytic activity. Herein, a visible light driven Nd-V-ZnO with spindle-like shape was synthesized by an ultrasonic assisted sol-gel method and characterized by XRD, SEM-EDS, TEM, UV-Vis DRS, FTIR and TGA-DTA techniques. The shift in optical response as well in XRD peaks validates the incorporation of metal ions into ZnO. The photocatalytic activity of synthesized materials was investigated by studying the degradation of three different pollutants such as rhodamine B (RhB), methyl orange (MO), and paracetamol in aqueous suspension with visible light illumination. The modified ZnO photocatalyst with 4% Nd and 1% V content shows excellent photocatalytic for the degradation of organic compounds. The substantial improvement in photocatalytic activity could be attributed to the extended visible light response and long-lived photogenerated charge carriers. In addition, the scavenging studies and photoluminescence terephthalic acid probe method revealed (OH)-O-center dot as the main reactive species involved in the degradation reaction. In addition, 4% Nd-V-ZnO photocatalyst showed reasonable photocatalytic activity for the degradation of RhB even after 4 cycle runs. A probable photocatalytic mechanism based on the radical trapping experiments for the degradation of pollutants has also been proposed.